In a stockpot, combine the backbones, onion, butter , and seasonings. Add the water, bring to a boil, cover, and cook at a low boil for 40 minutes. Add the rice to the pot and return to a boil, stirring well. Boil for 10 minutes, then reduce the heat, add green onions , cover the pot, and simmer for 10 minutes or until rice is done. Remove the bay leaves and serve.